TO_NUMBER

TO_NUMBER converts expr to a value of NUMBER data type. The expr can be a BINARY_DOUBLE value or a value of CHAR, VARCHAR2, NCHAR, or NVARCHAR2 data type containing a number in the format specified by the optional format model fmt.

You can specify an expr of BINARY_FLOAT. However, it makes no sense to do so because a float can be interpreted only by its internal presentation.

This function does not support CLOB data directly. However, CLOBs can be passed in as arguments through implicit data conversion.